The present invention relates to cover means for insulated portions in an automotive room lamp to be attached to the automobile roof panel made of a metal plate by way of a trim secured to the inner side thereof by fastening by screws, in which the automotive room lamp has plus side and minus side bus bars forming a lighting circuit such that said lighting circuit is not short circuit.
The conventional automotive room lamp is disclosed in Japanese Patent Application No. 2001-179774, in which the invention relates to an automotive lighting system and a method of producing the same. The automotive lighting system disclosed therein is characterized in that a plurality of bus bars having bridge portions are set in an integral form within a injection mold and said bridge portions are cut and bent up to form erect portions for holding the automotive lamp before resin is injected into the mold.
Another type of automotive room lamp is disclosed in Japanese Patent Application No. 2001-180372, in which the automotive room lamp disclosed therein is characterized in being composed of a one piece bus bar having terminals for connecting the switches and the power source therein, a holder to hold the lamp, said one piece bus bar having bridges for connecting lighting circuits; and a synthetic resin base member formed with apertures at positiones corresponding to said bridges in said bus bars set in a positioned manner such that said bridges are cut in said apertures after said bus bars are set in the base member.
It is to be noted in this connection that bridges are cut and bent up to separate the bus bar into the plus line and the minus line and that when the injection molded base member is fastened to the metal roof panel, tapping screws are used to cause metal chips to be produced. Such metal chips can fall onto the cut and bent up portions of bridges to cause short circuiting between the plus line and the minus line with the result that not only lighting of the lamp is impossible but fuse breaking or lamp breakdown takes place.
Further, the latter automotive lamp system has a problem that the holder for connecting the lamp to the bus bar sticks upward from the base member to the roof panel side to cause the holder to press upwardly from the lens side to the roof panel side, then causing short circuiting and fuse breaking because the body side including the roof panel is grounded.